BlackBerry Q5 with no SIM says it's on T-Mobile Network wtf?!

I just got a brand new sealed in the box blackberry Q5. I haven't activated it yet. All I have done with it so far is set it up and configure it. And it says it is on T-Mobile's network yet there isn't even a SIM card in the slot and I haven't even put one in there at all yet.

First of all I need to know why it says that because it makes me paranoid that someone is using its imei number on t-mobile if it works like that.

And just so you know this is a world unlocked phone bought straight from blackberry.